Winnick has a third degree black belt in tae kwon do, a second-degree black belt in karate, a degree in kinesiology (that's the science of human movement) and teaches women's self-defense classes. Still, when preparing for her first big action role alongside Kutcher and Katherine Heigl, Winnick trained four hours a day. (Fun fact: she also used to teach martial arts to actors!)

When she dropped by SELF, she gave us three tips every woman should know in case they're ever attacked:

Know where to hit. There are the obvious: the eyes, ears and, of course, groin, but you can also aim for the jugular--that little divet in the throat--and the ankle joint or the side of the knee, which are weak, unexpected spots.

Hold on to your keys. If your walking home alone when it's dark, keep your keys in your palm with individual keys poking out between fingers. That way, if someone grabs you, it packs more of a punch and you're more likely to get DNA from your attacker.

Roll up a magazine. With the binding rolled towards the inside, your favorite monthly read can hit someone with force equivalent to a steel rod. Now there's something you never thought your latest issue of SELF could do!

Check out Winnick's badass moves in the Killers trailer:

Winnick's secret agent skills can also help you slim down! Try Forza, a sweat session based on samurai-sword fighting that helps sculpt sexy muscle. Or drop pounds with a boxing-inspired martial arts workout. And show off your backside with a kick-butt capoeira workout.